Muffler



March 30, 1943. H, E. VAN VOORHEES 2,315,305

MUFFLER Filed May 7. 1941 3 Sheets-Sheet 1 lb I0 I v IO N IO

O I LI.

INVENTOR.

HAROLD E. VAN VOORHEES ATTORNE s March 30, 1943- H. E. VAN VOORHEES MUFFLER Filed May 7, 1941 3 Sheets-Sheet 2 INVENIOR. HAROLD E. VAN VOORHEES iwwu g 7 ATTORNEY March 30, 1943. VAN VOQRHEES 2,315,305

MUFFLER Filed y 1941 3 Sheets-Sheet 5 INVENTOR.

HAROLD E. VAN VOORHEES 5 g i2; Z: J

/ ATTORNEYS Patented Mar. 30, 1943 UNITED STATES PATENT OFFICE MUmER Harold E. Van Voorhees, Detroit, Mich.

Application May'7, 1841, Serial No. 392,374

10 Claim.

This invention relates generally to muiiiers and refers more particularly to those designed for mufliing the exhaust gases from internal combustion engines.

One of the essential objects of the invention is to provide a muiiier of this type wherein the impulses of the exhaust gases resulting from the explosions in the engine are separated and broken up into smaller impulses and conducted in streams of varying length through the mufiler without objectionable back pressure on the engine.

Another object is to provide a muflier that is simple in construction, economical to manufacture, and eflicient in operation.

Other objects, advantages and novel details of construction of this invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, wherein:

Figure 1 is a top plan view of a muiiier embodying my invention and having parts broken away to show the relative position and relation of parts within the outer shell thereof;

Figure 2 is a side elevation of the muffler illustrated in Figure 1 and showing by dotted lines the relative position and relation of parts within the outer shell thereof;

Figure 3 is a fragmentary plan view of one section of the outer shell;

Figure 4 is an end elevation of the section illustrated in Figure 3;

Figure 5 is a plan view of one section of the inner shell;

Figure 6 is an elevation of the section illustrated in Figure 5;

Figure '7 is an end elevation of the sections illustrated in Figures 5 and 6;

Figure 8 is a detail elevation of one of the frustums of the sound trap;

Figure 9 is a detail elevation of another frustum of the sound trap; I

Figure 10 is a detail elevation of another frustum of the sound trap;

Figure 11 is a rear elevation of the frustum illustrated in Figure 10;

Figure 12 is a side elevation of the cone of the sound trap;

Figure 13 is a rear elevation of the cone illustrated in Figure 12;

Figure 14 is a fragmentary elevation of the perforated tube;

Figure 15 is an end view of the tube illustrated in Figure 14;

Figure 16 is a sectional view taken on line Iii-i6 of Figure 14;

Figure 1'? is a fragmentary sectional view taken substantially on the line ll-r-il of Figure 1.

Referring now to the drawings, A is the outer shell, B is the inner shell, C is the perforated tube, D is the sound trap, and E and F, respectively, are deflectors of a muiiier embodying my invention.

As shown, the outer shell A is tubular in configuration except for opposite ends It and II thereof which are preferably rounded and have central openings l2 and I3, respectively, for suitable nipples II and It! to which the usual exhaust conduit sections (not shown) may be connected.

In the present instance, the outer shell A consists of two complementary stampings l8 and I1 and is stiffened and reinforced by a plurality of longitudinally spaced circumferentially extending channel-shaped embossed portions or ribs l8. The stampings l8 and I! are preferably light gauge sheet metal and have marginal flanges l9 and 20, respectively, seam-welded together.

The inner shell B is also tubular in configuration except for opposite ends 2| and 22 thereof, but is preferably much shorter than the outer shell A. As shown, the inner shell B is substantially concentric with the outer shell A so as to provide an annular space 23 therebetween and is located adjacent the forward end of said outer shell. In the present instance, opposite ends 2| and 22 of the inner shell are sleeved upon the perforated tube C which in turn is sleeved upon the nipple M at its inner end. The forward end 2| of the inner shell is provided with elongated openings 24 through which exhaust gases may pass from the interior of the shell B to the space 25 between the forward ends 2| and Hi, respectively, of the inner and outer shells. The rear end 22 of the inner shell is closed and imperforate. Preferably the inner shell B consists of two complementary stampings 26 and 21 and is stiffened and reinforced by a plurality of longitudinally spaced circumferentially extending channel-shaped embossed portions or ribs 28. The stampings 26 and 21 are light gauge sheet metal and have marginal flanges 29 seam-welded together.

The perforated tube C constitutes an inward extension of the nipple l4 and is provided throughout the major portion of its length with spaced circumferentially extending rows of openings 30, preferably arranged in pairs and provided with opposed outwardly projecting segmental louvers 3|.

or lugs SI and 38 located between and secured to g the annular flanges it and 31. By referring to Figures 1, 9, 11 and 13, respectively, it will be noted that the length of the registering lugs 38 and 38 is greater than the depth of the annular flange 31 of the outermost rearwardly projecting frustum 34, hence openings 40 are provided between the lugs for the passage of exhaust gases from the spaces II and 42, respectively, upon opposite sides of the innermost frustum 35 to the interior of the pocket 43 formed by the forwardly projecting frustum l2 and the rearwardly projecting cone 3!. If desired, the annular flange 36 of the forward frustum may be crimped over the outer edges or ends of the flange I1 and intermediate lugs 38 and 39. The innermost frustum 35 is sleeved upon and rigidly secured to the nipple llat its inner end. The cone SI and outermost frustum 34 are otherwise imperforate while the innermost frustum 35 has a circular series of circumferentially spaced, longitudinally extending, substantially V-shaped slots H through which exhaust gases may pass from the spaces 4| and 42 to the pocket 43.

The deflector E is substantially midway between the inner shell B and the sound trap D and preferably comprises a channel of circular configuration opening forwardly and having the outer walls thereof bearing against and rigidly secured to the outer shell A; The opening" provided at the center of the deflector E permits exhaust gases to pass from the annular space 23 between the inner and outer shells toward the sound trap D. In this connection it will be noted that the head 48 of the forward frustum 32 of the sound trap is in axial alignment with the opening 45 in the deflector E and is preferably concavo-convex in form so as to cooperate with the deflector E to direct or turn back exhaust gases and sound waves coming in contact therewith. Thus, the parts E and 48 are in reality reflectors.

The deflector F is between the sound trap D andthe rear end ll of the outer shell and is in the form of a hollow frustum of a cone sleeved upon and rigid with the nipple l5. Actually the deflector F serves as a protecting apron to prevent the direct reflection of sound into the space ll between the frustums 34 and 35.

In use, the exhaust gases and sound waves from the engine will flow from the nipple is into the perforated tube C from which they will pass through the openings 30 to the space 41 within the inner shell B and thence outwardly through the elongated openings 24 to the spaces 25 and 23 between the inner and outer shells. However, the tube openings and louvers ii are arranged in opposed pairs in such a way that the streams of exhaust gases and sound from the openings 30 will be directed in opposite directions against each other by the opposed louvers 3|. Thus, the head-on collision or contact of thereof before the gases enter the space I] within the inner shell and will cause much of the noise or sound waves created by the engine explosions to be dissipated or deflected within the tube 0, When flowing rearwardly in the space 23 between tlTe inner and outer shells, the gases and remaining sound waves will be broken up further by the transversely extending ribs II and 20. Such gases and sound waves will then be broken up further by contacting the deflector E and being directed thereby back against the closed end 22 of the inner shell. From this point they will flow through. the central opening ll in the deflector E against the deflector head of the sound trap where they will again be directed back and broken up further against the back of the deflector E to subsequently pass rearwardly around the sound trap D to the space ll. In this connection, some of the gases will pass the sound trap D and continue on beyond the deflector F to the rear end ll of the outer shell. However, ultimately such gases will enter the space II in the sound trap.

The function of the sound trap D is to de, flect the sound waves into the pocket 0 provided by the frustum I2 and cone I3 and to allow the gases to escape through the nipple II with the least possible back pressure. Thus, the gases and sound entering the space 4| between the frusturns 34 and II will strike the frustum II containing the slots 44. The gases and sound waves striking the surface of the frustum ll between the slots will be deflected directly through the openings 40 between the lugs into the pocket 0, while the gases and sound waves entering the slots 44 in the frustum ll will be deflected by the cone I3 through the openings 40 between the lugs into the pocket 43. A cushion of gas is thus built up in the pocket 43 and causes the gases which subsequently enter the slots 44 in the frustum N to reverse themselves and pass out through the nipple II to a suitable exhaust conduit (not shown).

What I claim as my invention is:

1. A muiiier having an elongated shell, a tube for exhaust gases extending through an end of said shell, and a sound trap carried by the inner end of the tube within said shell, said trap including a forwardly projecting frustum of a cone having a concave-convex head and having an annular attaching flange, a rearwardly projecting cone having radially projecting attaching lugs disposed in surface-to-surface engagement with and secured to the flange of the frustum, and inner and outer rearwardly projecting frustums of cones encircling the rearwardly projecting cone, the inner frustum having radially extending attaching lugs registering with and secured to the lugs of the rearwardly projecting cone, the outer frustum having an annular attaching flange disposed in surface-to-surface engagement with and secured to the lugs of the inner frustum. and the length of the registering lugs being greater than the depth of the annular flange of the rearwardly projecting outer frustum so that openings for exhaust gases are provided between the rearwardly projecting cone and the outer frustu'm.

2. A muliier having an elongated shell provided with inlet and outlet openings respectively for exhaust gases, an exhaust tube extending inwardly through the outlet opening of said shell,-

. and a sound trap at the inner end of the tube such streams will tend to neutralize the fo ces within said shell, said trap including a forwardly projecting frustum of a cone having an annular a,a1s,sos

5..A mufller having a tubular outer shell proattaching flange, a rearwardly projecting cone cooperating with the forwardly projecting frustum to, form a pocket or chamber and having radially projecting attaching lugs disposed in surface-to-surface engagement with and secured to the flange of the frustum, and inner and outer rearwardly projecting frustums of cones encircling the rearwardly projectingcone, the inner frustum being mounted on the exhaust tube at its inner end and constituting a support for the other elements of said sound trap, said inner frustum having radially extending attaching lugs registering with and secured to the lugs of the rearwardly projecting cone and having slots therein through which exhaust gases may flow to said exhaust tube, the outer frustum having an annular attaching flange disposed in surface to-surface engagement with and secured to the lugs of the inner frustum, and the length of the registering lugs being greater than the depth of aforesaid.

3. A muffler having an elongated shell provided with inlet and outlet openings respectively for exhaust gases, an exhaust tube extending inwardly through the outlet opening of said shell, and a sound trap at the inner end of said tube within said shell, said trap including a forwardly projecting frustum of a cone, a rearwardly projecting cone cooperating with the forwardly pro- .l'ecting frustum to form a pocket or chamber, and inner and outer rearwardly projecting frustums of cones encircling the rearwardly projecting cone, the forwardly projecting frustum, rear- Wardly projecting cone and inner and outer frustums being secured together as a unit, the inner frustum being mounted on the exhaust tube at its inner end and constituting a support for the other elements of said sound trap, said inner frustum having slotstherein through which exhaust gases may flow to. said exhaust tube, the rearwardly projecting cone and inner rearwardly projecting frustum being provided with openings through which exhaust gases may flow from the space between the inner and outer rearwardly projecting frustums to the interior of the pocket or chamber aforesaid, said inner and. outer rearwardly projecting frustums cooperating with each other to form an inlet for exhaust gases to the slots and openings mentioned.

4. A muffier having an elongated shell provided with inlet and outlet openings respectively for exhaust gases, an exhaust tube extending inwardly through the outlet opening of said shell, and a sound trap within said shell at the inner end of and substantially in axial alignment with said exhaust tube and comprising a pocket or chamber, and inner and outer rearwardly projecting frustums of cones encircling and secured to said pockets, the inner frustum being mounted on the exhaust tube at its inner end and constituting a support for the pocket, said inner frustum having slots therein through which exhaust gases may now to said exhaust tube, said pocket being provided adjacent said slots with openings through whichexhaust gases may flow to the interior of said pocket, and the inner and outer frustums cooperating with each other to form an inlet for exhaust gases to the slots and openings aforesaid.

vided at opposite ends thereof with inlet and outlet openings respectively for exhaust gases, nipples for exhaust gases extending through said inlet and outlet openings into said shell and secured to the latter, a perforated tube within said shell and forming an endwise extension of the nipple at the forward end of the shell, an inner shell substantially concentric with the perforated tube and having its opposite ends sleeved upon and secured to said tube adjacent opposite ends thereof, the forward end of the inner shell having one or more openings therein through which exhaust gases may flow. from the interior of the inner shell to the space between the inner and outer shells, the rear end of said inner shell being closed and constituting a closure for the inner end of the perforated tube, and a sound trap within the outer shell between the rear end thereof and the closed rear end of the inner shell and including a pocket or chamber between and substantially in axial alignment with the inner shell and the nipple at the rear end of the outer shell, said pocket having one or more inlet openings for exhaust gases, and a support for said pocket carried by the nipple at the rear end of the outer shell and having openings through which exhaust gases may flow to the nipple at the rear end of the outer shell.

6. A muflier having a tubular outer shell provided at opposite ends thereof with inlet and outlet openings respectively for exhaust gases, a perforated tube extending axially of said outer shell from the inlet opening thereof to a point short of the rear end thereof, a tubular inner shell sleeved on said tube within and substantially concentric with the outer shell so that an annular space for exhaust gases is provided between said shells, the inner shell being substantially equal in length to the tube and provided at the rear end of said tube with a closed end. said inner shell being adapted to receive exhaust gases from the perforations in said tube and being provided at its forward end with an opening through which such exhaust gases may pass to the annular space aforesaid, means within the outer shell between the rear end thereof and the closed end of the inner shell for receiving and eliminating noise frdm the-exhaust gases from the annular space aforesaid, and means for conducting the exhaust gases from the noise eliminating means just mentioned to the outlet opening in the outer shell.

7. A muilier having a tubular outer shell provided at opposite ends thereof with inlet and outlet openings respectively for exhaust gases, a perforated tube extending axially of said outer shell from the inlet opening thereof to a point short of the rear end thereof, a tubular inner shell sleeved on said tube within and-substantially concentric with the outer shell so that an annular space for exhaust gases is provided between said shells, the inner shell being substantially equal in length to the tube and provided at the rear end of said tube with a closed end, said inner shell being adapted to receive exhaust gases from the perforations in said tube and being provided at its forward end with an opening through which such exhaust gases may pass to the annular space aforesaid, both the inner and outer shells having longitudinally spaced transversely extending ribs for breaking up the exhaust gases flowing longitudinally of the annular space between said innerand outer shells, means within thecuter shell between the rear end thereof and the closed end of the inner shell for receiving exhaust gases from the annular space aforesaid, and means for conducting theexhaust gases from the means just mentioned to the outlet opening in the outer shell,

8. A muiller having a tubular outer shell provided at opposite ends thereof with inlet and outlet openings respectively for exhaust gases, a perforated tube extending axially of said outer shell from the inlet opening thereof to a point short of the rear end thereof, a tubular inner shell sleeved on said tube within and substantially concentric with the outer shell so that an annular space for exhaust ases is provided between said shells, the inner shell being substantially equal in length to the tube and provided at the rear end of said tube with a closed end, said inner shell being adapted to receive exhaust gases from the perforations in said tube and being provided at its forward end with an opening through which such exhaust gases may pass to the annular space aforesaid, an exhaust tube extending inwardly through the outlet opening at the rear end of the outer shell, 9, sound trap within the outer shell in the space between the rear end thereof and the closed rear end of the inner shell and including a pocket or chamber between and substantially in axial alignment with the inner shell and exhaust tube and having inlet openings for exhaust gases from the last mentioned space within the outer shell, and a support for said pocket having means for directing exhaust gases from the last mentioned space to the inlet openings of said pocket and having means permitting the exhaust gases to flow from the last mentioned space into said exhaust tube.

9. A muiller having a tubular outer shell provided at opposite ends thereof with inlet and outlet openings respectively for exhaust gases, a perforated tube extending axially of said outer shell from the inlet opening thereof to a point short of the rear end thereof, a tubular inner shell sleeved on said tube within and substantially concentric with the outer shell so that an annular space for exhaust gases is provided between said shells,4:he inner shell being substantially equal in length to the tube and provided at the rear end of said tube with a closed end, said inner shell being adapted to receive exhaust gases from the perforations in said tube and being provided at its forward end with an opening through which such exhaust gases may pass to the annular space aforesaid, an exhaust tube extending inwardly through the outlet opening at the rear end of the outer shell, a sound trap within the outer shell in the space between the rear end thereof and the closed rear end of the inner shell and including a pocket or chamber between and substantially in axial alignment with the inner shell and exhaust tube and having inlet openings for exhaust gases from the last mentioned space within the outer shell, a support for said pocket having means for directing exhaust gases from the last mentioned space to the inlet openings of said pocket and having means permitting the exhaust gases to flow from the last mentioned space into said exhaust tube, a deflector for the exhaust gases within the outer shell between the closed end of the inner shell and the sound trap, said deflector having a. channel-shaped portion opening toward and substan tially in longitudinal li nment with the annular space between the innerand outer shells for turning back toward said space the exhaust gases received therefrom and having in substantially axial alignment with the closed end of the inner shell an opening through which exhaust gases may flow toward the sound trap.

10. A mufler having a tubular outer shell provided at opposite ends thereof with inlet and outlet openings respectively for exhaust gases, a perforated tube extending axially of said outer shell from the inlet opening thereof to a point short of the rear end thereof, a tubular inner shell sleeved on said tube within and substantially concentric with the outer shell so that an annular space for exhaust gases is provided between said shells, the inner shell being substantially equal in length to the tube and provided at the rear end of said tube with a closed end, said inner shell being adapted to receive exhaust gases from the perforations in said tube and being provided at its forward end, with an opening through which such exhaust gases may pass to the annular space aforesaid, an exhaust tube extending inwardly through the outlet opening at the rear end of the outer shell, a sound trap within the outer shell in the space between the rear end thereof and the closed rear end of the inner shell and including a pocket or chamber between and substantially in axial alignment with the inner shell and exhaust tub and hflVinC inlet p nings for exhaust gases from the last mentioned space within the outer shell, a support for said pocket having -means for directing exhaust gases from the last mentioned space to the inlet openings of said pocket and havin means permitting the exhaust gases to flow from the last mentioned space into said exhaust tube,

- a deflector for the exhaust gases within the outer shell between the closed end of the inner shell and the sound trap, said deflector having a channel-shaped portion opening toward and substan tially in longitudinal alignment with the annular space between the inner and outer shells for turning back toward said space the exhaust gases received therefrom and having in substantially axial alignment with the closed end of the inner shell an opening through which exhaust gases may flow toward the sound trap, the forward portion or head of the pocket being, substantially in axial alignment with the opening just mentioned in said deflector and having a concave portion facing toward said opening for turning back toward said opening the exhaust gases received therefrom.

HAROLD E. VAN VOORHEES. 

